diff --git a/src/main/java/au/com/royalpay/payment/manage/application/core/impls/SimpleClientApplyServiceImpl.java b/src/main/java/au/com/royalpay/payment/manage/application/core/impls/SimpleClientApplyServiceImpl.java
index 21561226e..22b1bb925 100644
--- a/src/main/java/au/com/royalpay/payment/manage/application/core/impls/SimpleClientApplyServiceImpl.java
+++ b/src/main/java/au/com/royalpay/payment/manage/application/core/impls/SimpleClientApplyServiceImpl.java
@@ -163,6 +163,9 @@ public class SimpleClientApplyServiceImpl implements SimpleClientApplyService {
         if (client == null) {
             throw new BadRequestException("Merchant not found");
         }
+        if(client.getBooleanValue("mail_confirm")){
+           throw new BadRequestException("mail address has been verified");
+        }
         String key = checkOrGenerateVerifyMailKey(address, null);
         Context ctx = new Context();
         ctx.setVariable("url", PlatformEnvironment.getEnv().concatUrl("/register/account/mail/" + address + "/verify/" + key + "/jump?username="+username));
@@ -292,6 +295,7 @@ public class SimpleClientApplyServiceImpl implements SimpleClientApplyService {
         sysClient.put("merchant_id", availableMerchant.getMerchantId());
         sysClient.put("sub_merchant_id",tempSubMerchantId);
         sysClient.put("common_sub_merchant_id",1);
+        sysClient.put("credential_code", RandomStringUtils.random(32, true, true));
         clientMapper.save(sysClient);
 
         int clientId = sysClient.getIntValue("client_id");